Marauder Posted August 17, 2015 Report Posted August 17, 2015 When I had the GNC 255 installed, the sidetone was really low on my Halo headset. I had the sidetone adjusted and flew with all of my headsets I own; the Halo, my LightSpeed Zulu, a Telex MD-50 and my Clark ANR. I had a fixed point I transmitted at and had a Unicom base station tell me how I sounded. The Clark, LS and Telex all were comparable. The station reported the Clark and Telex were the clearest, followed by the Zulus (not far behind). The Halo in the other hand was reported as noticeable weaker. Am I dealing with a bad mic or is there something unique about the design of the Clark, Telex and LightSpeed that make them better? Sent from my iPad using Tapatalk Quote
N601RX Posted August 17, 2015 Report Posted August 17, 2015 Most headsets will also have a mic gain on them. It may be under the mic muff. Quote
ArtVandelay Posted August 17, 2015 Report Posted August 17, 2015 How does the mics sound thru the intercom?? Quote
Marauder Posted August 17, 2015 Author Report Posted August 17, 2015 How does the mics sound thru the intercom?? The Zulus sounded the best and the Halo's the worst. Sent from my iPad using Tapatalk Quote
Marauder Posted August 17, 2015 Author Report Posted August 17, 2015 Most headsets will also have a mic gain on them. It may be under the mic muff. Thanks Mike. I will pull the mitt off of the Halos and see what is there. Sent from my iPad using Tapatalk Quote
Marauder Posted August 17, 2015 Author Report Posted August 17, 2015 BTW -- with the recent 90+ temps and high humidity, I would love the Halos to be my headset of choice. Sent from my iPad using Tapatalk Quote
ArtVandelay Posted August 17, 2015 Report Posted August 17, 2015 Good, then we can eliminate the radios and testing becomes trivial The Zulus sounded the best and the Halo's the worst. Zulus have a mic adjustment, Bose do not (I think they auto adjust). dont know about Halos. BTW, the mics are very uni-directional, make sure its pointed at your mouth, easy to do because the mitt covers the mic and you may not have notice. 1 Quote
N601RX Posted August 17, 2015 Report Posted August 17, 2015 I'm not familiar with the Halo's, but with the Zulu once you remove the muff there is a little round cover that has an adjustment under it. The mic is also very directional to avoid picking up noise so be sure it is pointed at you and not up or down. 1 Quote
Oscar Avalle Posted August 17, 2015 Report Posted August 17, 2015 I agree, mics are very different. Even between the old Bose A20 and the new ones. Halos are the worst. Their sound quality is not so great compared to the Bose. On the other hand in hot weather they are a great choice. As mentioned before you have to make sure that they are pointed in the right direction and close to you mouth. Quote
Marauder Posted August 17, 2015 Author Report Posted August 17, 2015 I agree, mics are very different. Even between the old Bose A20 and the new ones. Halos are the worst. Their sound quality is not so great compared to the Bose. On the other hand in hot weather they are a great choice. As mentioned before you have to make sure that they are pointed in the right direction and close to you mouth. Thanks Oscar. I will check on the directional piece of this. I was a bit disappointed after dropping a good chunk of change on a new radio to find people saying that the transmission was weak. Sent from my iPad using Tapatalk Quote
gsxrpilot Posted August 17, 2015 Report Posted August 17, 2015 The mics on the Halos are VERY directional. If it's just slanted away from you either up or down it will be noticeably poor. And if it's 90 degrees to your mouth it won't work at all. Â My wife tried my Halo's once and decided she liked them much better than the Zulu2's I had handed down to her after getting the Halo's for me. So I let her use the Halo's and I went back to the Zulu's, planning to buy another set of Halo's at Oshkosh this year. On the trip to OSH her mic stopped working. It was the same over several flights. At the show, I went to the QT booth and complained about he mic not working anymore. He tested them and showed me that the mic boom had gotten twisted and was 90 degrees to the mouth. Now that I felt completely ignorant ;-) we bought a second pair and headed home. Now we both use the Halos and the Zulu2 is designated as the loaner headset for passengers. 1 Quote
MB65E Posted August 17, 2015 Report Posted August 17, 2015 I have always liked the DC microphones! I used a boom DC mic on my helmet I built up. The stock military style Mic was garbage and would not work with the gtn650. The DC mic was much better with the GTN's. -Matt. 1 Quote
N201MKTurbo Posted August 17, 2015 Report Posted August 17, 2015 There are dynamic, carbon and electret mics. Carbon and electret mics need DC voltage applied. All radios supply mic voltage. Mics need to be directional and noise canceling to work in an airplane. Otherwise all they would pick up is engine and wind noise. They accomplish noise canceling by letting cabin noise get to both sides of the diaphragm. The noise will be in phase on both sides so it will cancel. The sound from your mouth needs to get to only one side of the diaphragm or else it would also cancel itself out. This is accomplished by physically separating the two ports one towards your mouth and one away from your mouth. This is why there are ports on the back side of the mic. They make the mic directional by the size and shape of the ports to further increase the ratio of mouth sound getting to the front vs the back. How you place the mic with relation to your mouth can have a big effect on how well the mic works. 3 Quote
Marauder Posted August 17, 2015 Author Report Posted August 17, 2015 The Halo mics are hard to beat. They are the exact same electret noise canceling microphone used by 90 percent of all other headset manufacturers on the market`. They are clearer than most other mics and this has been reported on by several magazines including Aviation Consumer has being one of the clearest mics. This is because we operate the mic frequency response at the broadest extents of the allowable envelope. In other words, it has more highs and lows than most other mics lending to a much more intelligible sound than most other mics with narrower frequency responses. Being a TRUE bidirectional mic, you need to accurately position the mic near your mouth with the LARGE hole pointed toward your mouth. Like all mics, it needs to be about 1/2" from your lips. The mic can work itself out of axis and you will find yourself speaking into the side of the mic. If you do, your gain can drop to ZERO, so speak into the large hole. Fell through the foam wind screen if you have any doubts as to the orientation. Gain sensitivity is set to the mid range of the RTCA specifications used as a reference specification for TSO certification. It says a 1KHz signal presented at 94 dB SPL shall produce "x" amount of voltage output +/- However, the specification fails to mention whether the output is peak, peak to peak, average, RMS etc. It also allows for a large range of acceptable voltage min and maximums. What this means is that there is a tremendous variability allowed within the specification itself and hence the reason why there is a large variability between manufacturers' mic sensitivity. The Halo is set pretty close to down the line middle of the road. However, having a fixed gain mic becomes a problem when you try to get an intercom with an "automatic" squelch control. Seems as if brand "x" is never set for the headset you have and is better suited for the other brand "x" headset mics you don't have. It is a problem for us at QT because while we want our headset to work for EVERYONE under ALL conditions, this is next to impossible. If I were to set the gain to work with an automatic squelch intercom of brand "x". then it will be WAY too loud for those guys using it on a "hot mic" system in the ERJ /CRJ jets. Can't get everyone happy with what we do, but fortunately, an overwhelming majority of users report excellent result with the Halo mic as is. BTW, there is currently no provision for a manual mic gain control on the Halo. Proper positioning (not speaking into the side of the mic) will produce the best results on the Halo. Phil Mc Thanks Phil! Now that's what I call an education. I will check the orientation of the mic and report back. I am using a PS Engineering 8000BT for the intercom and a GTN 650 along with the GNC 255. The unit performs the same on both radios. Sent from my iPad using Tapatalk Quote
Piloto Posted August 17, 2015 Report Posted August 17, 2015 The foam cover over the mic keeps the blowing air from sounding into the mic. Without it the ventilation breeze and blowing air when you talk will be noisy on the mic. Always keep the foam cover on it.  José Quote
carusoam Posted August 17, 2015 Report Posted August 17, 2015 Holy Cow! There is still so much more to learn. I like my silicone ear buds in my Halo(s) the best. Thank you gents for the input. Best regards, -a- Quote
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